An operation (process) as a result of which microcomponents are selectively isolated from a sample. It is used when the simultaneous presence of several components in the concentrate may distort the results of analysis. Selective preconcentration usually is achieved by isolation of the microcomponent to be determined.
PAC, 1979, 51, 1195. 'Separation and Preconcentration of Trace Substances. I-Preconcentration for Inorganic Trace Analysis' on page 1197 (https://doi.org/10.1351/pac197951051195)